The invention relates to a rope for the taking along and transferring of paper webs in the manufacture on paper machines of paper and cardboard made from round-braided textile fiber material.
Ropes from braided textile fiber material are known in the most varied configurations. A rope is known for example from DE 40 35 814 A1 comprising a core and a particularly braided sheath, the core being formed with low strain, ie possessing a low stretch behavior and a high modulus of elasticity. The object of this prior art is the reduction of the relative movement between a core and a sheath surrounding it, particularly during the clamping of the rope on the sheath. The core and the sheath are formed from a number of thin polyamide fibers collected as different units of the fiber rope. The sheath is formed from a mixture of low stretching and normally stretching. The number of low stretching is particularly 17% to 25%. In this way, the stretch behavior of the sheath is reduced to such an extent that it corresponds to that of the core, by which means a relative movement due to different stretching is prevented. At the same time, however, the friction coefficients of the core and the sheath are approximated to each other. The fibers can also consist of polyethylene or polypropylene.
DE 25 05 568 A1 reveals the creation of cable structures serving as armoring for solid, elastic or easily deformed materials (eg cord for automobile tires) and possessing increased resistance to fatigue and/or wear. The basic concept here can be found in the reduction of the radial pressures or compression forces prevailing between the construction layers of a cable and between these and the core. The components of a cable, ie the core and at least one outside layer are designed in such a way that at least two successive components contacting each other radially are made from materials with different moduli of elasticity. In this way, as one component is "softer", contact areas between two components are increased and the surface pressure reduced.
AT 367 112 B relates to the increase of the service life of a rope made from aromatic polyarnide with multiple layers of rope elements laid to a rope over a core. The rope comprises a heart strand, an inner strand layer laid around the heart strand with a twist and made up of strands, an outer strand layer outwardly bounding the inner strand layer and also comprising strands possessing a twist rning parallel to the twist of the strands of the inner strand layer, and monofilament bundles positioned between the inner and outer strand layers. The heart strand and the strands of the inner and outer strand layers are comprised of monofilament bundles. In this way, the surface pressure on the guidelines is reduced resulting in an increase in the service life.
U.S. Pat. No. 4,563,869 relates to a cordage, particularly to a heavy duty marine rope, with safety features in order to save people from damage due to rope breakage. When all components of a rope break at the same time, the two separate rope pieces fly away from the point of breakage at an enormous speed thus exposing any persons in the area to a great risk. It is proposed here to make a multiple component rope, preferably from a synthetic material comprising a certain number of components with a high stretch and a certain number of components with a relatively low stretch with the quantity of the latter components being predominant. In accordance with a further development of this idea, the outer skeins of the rope possess a plurality of covering threads formed from a material with a higher wear resistance.
Finally, a method is known from DE 35 13 093 A1 for the manufacture of a gradient cable as the drive element of automobile sun roofs which is claimed to be sound-absorbent and wear resistant. With a device to perform the method, a gradient cable moved in longitudinal extension is sheathed with a flocked thread. To do this, a plate with a coil taking up the thread rotates around the centre axis of the gradient cable.
In addition to the application in the different areas described above, it is known to use so-called paper guide ropes for the taking along and transferring of paper webs in the manufacture of paper and cardboard on paper machines. These ropes normally run in rope guiding systems on one of the two long sides of a paper machine. The main object of such ropes is to clamp the formed paper web by means of a suitable rope guidance and composition and so to transport it again through the individual sections of the paper machine after start of travel or after tear-offs. The so-called paper guide ropes must meet special demands which can be summarized as follows:
longest possible service life at running speeds of up to 2,500 m/min; PA1 low operating stretch of the ropes so that the limited tension ways of the rope tightening stations are sufficient without falling below the required rope tension; PA1 temperature, humidity and chemical resistance under the usual conditions in paper or cardboard manufacture; PA1 good chafmg or wear resistance towards the guiding rollers of the rope guidance systems and PA1 good splicing capability of the rope ends to achieve an endless rope.
In addition to these special requirements, in all cases of application of the so-called paper guide rope, it is decisive that the paper or cardboard web can be clamped without problems when the paper manufacturing process is started and taken along from one section of the paper machine to the next section. Experience shows that one to up to 10 sections follow successively with the number of sections depending on the type of paper machine and on the quality of the paper and the cardboard. The standard rope lengths per section fluctuate between 30 m and 700 m, with the paper guide ropes being used in different rope guide system constructions (eg one-rope systems, two-rope systems or three-rope systems).
Basically, the so-called paper guide ropes textile fiber material with both fibers on a cellulose base and fibers made from organic chain polymers such as polyacrylate, polyamnide, polyester, polypropylene, polyethylene, polyvinyl alcohol or similar being used. The ropes used as paper guide ropes comprise on the one hand twisted or laid strands and on the other hand braided ropes. The braided ropes can be used as braided hollow ropes or also in the form of ropes in core/sheath designs.
Worldwide, the braided paper guide ropes have been successful over twisted ropes as a result of their high service life, their low operating stretch, their exceptional chafing and wear resistance and their simple splicing capability. However there are also some cases of design-caused relationships on paper machines where twisted ropes are given preference, as due to the more roughly structured surface of the twisted ropes advantages occur in paper web clamping over the comparatively smoother structure of braided ropes.